# revlog.py - storage back-end for mercurial # # Copyright 2005-2007 Matt Mackall # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. """Storage back-end for Mercurial. This provides efficient delta storage with O(1) retrieve and append and O(changes) merge between branches. """ # import stuff from node for others to import from revlog from node import bin, hex, nullid, nullrev, short #@UnusedImport from i18n import _ import changegroup, ancestor, mdiff, parsers, error, util import struct, zlib, errno _pack = struct.pack _unpack = struct.unpack _compress = zlib.compress _decompress = zlib.decompress _sha = util.sha1 # revlog header flags REVLOGV0 = 0 REVLOGNG = 1 REVLOGNGINLINEDATA = (1 << 16) REVLOGSHALLOW = (1 << 17) REVLOG_DEFAULT_FLAGS = REVLOGNGINLINEDATA REVLOG_DEFAULT_FORMAT = REVLOGNG REVLOG_DEFAULT_VERSION = REVLOG_DEFAULT_FORMAT | REVLOG_DEFAULT_FLAGS REVLOGNG_FLAGS = REVLOGNGINLINEDATA | REVLOGSHALLOW # revlog index flags REVIDX_PARENTDELTA = 1 REVIDX_PUNCHED_FLAG = 2 REVIDX_KNOWN_FLAGS = REVIDX_PUNCHED_FLAG | REVIDX_PARENTDELTA # amount of data read unconditionally, should be >= 4 # when not inline: threshold for using lazy index _prereadsize = 1048576 # max size of revlog with inline data _maxinline = 131072 RevlogError = error.RevlogError LookupError = error.LookupError def getoffset(q): return int(q >> 16) def gettype(q): return int(q & 0xFFFF) def offset_type(offset, type): return long(long(offset) << 16 | type) nullhash = _sha(nullid) def hash(text, p1, p2): """generate a hash from the given text and its parent hashes This hash combines both the current file contents and its history in a manner that makes it easy to distinguish nodes with the same content in the revision graph. """ # As of now, if one of the parent node is null, p2 is null if p2 == nullid: # deep copy of a hash is faster than creating one s = nullhash.copy() s.update(p1) else: # none of the parent nodes are nullid l = [p1, p2] l.sort() s = _sha(l[0]) s.update(l[1]) s.update(text) return s.digest() def compress(text): """ generate a possibly-compressed representation of text """ if not text: return ("", text) l = len(text) bin = None if l < 44: pass elif l > 1000000: # zlib makes an internal copy, thus doubling memory usage for # large files, so lets do this in pieces z = zlib.compressobj() p = [] pos = 0 while pos < l: pos2 = pos + 2**20 p.append(z.compress(text[pos:pos2])) pos = pos2 p.append(z.flush()) if sum(map(len, p)) < l: bin = "".join(p) else: bin = _compress(text) if bin is None or len(bin) > l: if text[0] == '\0': return ("", text) return ('u', text) return ("", bin) def decompress(bin): """ decompress the given input """ if not bin: return bin t = bin[0] if t == '\0': return bin if t == 'x': return _decompress(bin) if t == 'u': return bin[1:] raise RevlogError(_("unknown compression type %r") % t) class lazyparser(object): """ this class avoids the need to parse the entirety of large indices """ # lazyparser is not safe to use on windows if win32 extensions not # available. it keeps file handle open, which make it not possible # to break hardlinks on local cloned repos. def __init__(self, dataf): try: size = util.fstat(dataf).st_size except AttributeError: size = 0 self.dataf = dataf self.s = struct.calcsize(indexformatng) self.datasize = size self.l = size // self.s self.index = [None] * self.l self.map = {nullid: nullrev} self.allmap = 0 self.all = 0 self.mapfind_count = 0 def loadmap(self): """ during a commit, we need to make sure the rev being added is not a duplicate. This requires loading the entire index, which is fairly slow. loadmap can load up just the node map, which takes much less time. """ if self.allmap: return end = self.datasize self.allmap = 1 cur = 0 count = 0 blocksize = self.s * 256 self.dataf.seek(0) while cur < end: data = self.dataf.read(blocksize) off = 0 for x in xrange(256): n = data[off + ngshaoffset:off + ngshaoffset + 20] self.map[n] = count count += 1 if count >= self.l: break off += self.s cur += blocksize def loadblock(self, blockstart, blocksize, data=None): if self.all: return if data is None: self.dataf.seek(blockstart) if blockstart + blocksize > self.datasize: # the revlog may have grown since we've started running, # but we don't have space in self.index for more entries. # limit blocksize so that we don't get too much data. blocksize = max(self.datasize - blockstart, 0) data = self.dataf.read(blocksize) lend = len(data) // self.s i = blockstart // self.s off = 0 # lazyindex supports __delitem__ if lend > len(self.index) - i: lend = len(self.index) - i for x in xrange(lend): if self.index[i + x] is None: b = data[off : off + self.s] self.index[i + x] = b n = b[ngshaoffset:ngshaoffset + 20] self.map[n] = i + x off += self.s def findnode(self, node): """search backwards through the index file for a specific node""" if self.allmap: return None # hg log will cause many many searches for the manifest # nodes. After we get called a few times, just load the whole # thing. if self.mapfind_count > 8: self.loadmap() if node in self.map: return node return None self.mapfind_count += 1 last = self.l - 1 while self.index[last] != None: if last == 0: self.all = 1 self.allmap = 1 return None last -= 1 end = (last + 1) * self.s blocksize = self.s * 256 while end >= 0: start = max(end - blocksize, 0) self.dataf.seek(start) data = self.dataf.read(end - start) findend = end - start while True: # we're searching backwards, so we have to make sure # we don't find a changeset where this node is a parent off = data.find(node, 0, findend) findend = off if off >= 0: i = off / self.s off = i * self.s n = data[off + ngshaoffset:off + ngshaoffset + 20] if n == node: self.map[n] = i + start / self.s return node else: break end -= blocksize return None def loadindex(self, i=None, end=None): if self.all: return all = False if i is None: blockstart = 0 blocksize = (65536 / self.s) * self.s end = self.datasize all = True else: if end: blockstart = i * self.s end = end * self.s blocksize = end - blockstart else: blockstart = (i & ~1023) * self.s blocksize = self.s * 1024 end = blockstart + blocksize while blockstart < end: self.loadblock(blockstart, blocksize) blockstart += blocksize if all: self.all = True class lazyindex(object): """a lazy version of the index array""" def __init__(self, parser): self.p = parser def __len__(self): return len(self.p.index) def load(self, pos): if pos < 0: pos += len(self.p.index) self.p.loadindex(pos) return self.p.index[pos] def __getitem__(self, pos): return _unpack(indexformatng, self.p.index[pos] or self.load(pos)) def __setitem__(self, pos, item): self.p.index[pos] = _pack(indexformatng, *item) def __delitem__(self, pos): del self.p.index[pos] def insert(self, pos, e): self.p.index.insert(pos, _pack(indexformatng, *e)) def append(self, e): self.p.index.append(_pack(indexformatng, *e)) class lazymap(object): """a lazy version of the node map""" def __init__(self, parser): self.p = parser def load(self, key): n = self.p.findnode(key) if n is None: raise KeyError(key) def __contains__(self, key): if key in self.p.map: return True self.p.loadmap() return key in self.p.map def __iter__(self): yield nullid for i, ret in enumerate(self.p.index): if not ret: self.p.loadindex(i) ret = self.p.index[i] if isinstance(ret, str): ret = _unpack(indexformatng, ret) yield ret[7] def __getitem__(self, key): try: return self.p.map[key] except KeyError: try: self.load(key) return self.p.map[key] except KeyError: raise KeyError("node " + hex(key)) def __setitem__(self, key, val): self.p.map[key] = val def __delitem__(self, key): del self.p.map[key] indexformatv0 = ">4l20s20s20s" v0shaoffset = 56 class revlogoldio(object): def __init__(self): self.size = struct.calcsize(indexformatv0) def parseindex(self, fp, data, inline): s = self.size index = [] nodemap = {nullid: nullrev} n = off = 0 if len(data) == _prereadsize: data += fp.read() # read the rest l = len(data) while off + s <= l: cur = data[off:off + s] off += s e = _unpack(indexformatv0, cur) # transform to revlogv1 format e2 = (offset_type(e[0], 0), e[1], -1, e[2], e[3], nodemap.get(e[4], nullrev), nodemap.get(e[5], nullrev), e[6]) index.append(e2) nodemap[e[6]] = n n += 1 return index, nodemap, None def packentry(self, entry, node, version, rev): if gettype(entry[0]): raise RevlogError(_("index entry flags need RevlogNG")) e2 = (getoffset(entry[0]), entry[1], entry[3], entry[4], node(entry[5]), node(entry[6]), entry[7]) return _pack(indexformatv0, *e2) # index ng: # 6 bytes: offset # 2 bytes: flags # 4 bytes: compressed length # 4 bytes: uncompressed length # 4 bytes: base rev # 4 bytes: link rev # 4 bytes: parent 1 rev # 4 bytes: parent 2 rev # 32 bytes: nodeid indexformatng = ">Qiiiiii20s12x" ngshaoffset = 32 versionformat = ">I" class revlogio(object): def __init__(self): self.size = struct.calcsize(indexformatng) def parseindex(self, fp, data, inline): if len(data) == _prereadsize: if util.openhardlinks() and not inline: # big index, let's parse it on demand parser = lazyparser(fp) index = lazyindex(parser) nodemap = lazymap(parser) e = list(index[0]) type = gettype(e[0]) e[0] = offset_type(0, type) index[0] = e return index, nodemap, None else: data += fp.read() # call the C implementation to parse the index data index, nodemap, cache = parsers.parse_index(data, inline) return index, nodemap, cache def packentry(self, entry, node, version, rev): p = _pack(indexformatng, *entry) if rev == 0: p = _pack(versionformat, version) + p[4:] return p class revlog(object): """ the underlying revision storage object A revlog consists of two parts, an index and the revision data. The index is a file with a fixed record size containing information on each revision, including its nodeid (hash), the nodeids of its parents, the position and offset of its data within the data file, and the revision it's based on. Finally, each entry contains a linkrev entry that can serve as a pointer to external data. The revision data itself is a linear collection of data chunks. Each chunk represents a revision and is usually represented as a delta against the previous chunk. To bound lookup time, runs of deltas are limited to about 2 times the length of the original version data. This makes retrieval of a version proportional to its size, or O(1) relative to the number of revisions. Both pieces of the revlog are written to in an append-only fashion, which means we never need to rewrite a file to insert or remove data, and can use some simple techniques to avoid the need for locking while reading. """ def __init__(self, opener, indexfile, shallowroot=None): """ create a revlog object opener is a function that abstracts the file opening operation and can be used to implement COW semantics or the like. """ self.indexfile = indexfile self.datafile = indexfile[:-2] + ".d" self.opener = opener self._cache = None self._chunkcache = (0, '') self.nodemap = {nullid: nullrev} self.index = [] self._shallowroot = shallowroot self._parentdelta = 0 v = REVLOG_DEFAULT_VERSION if hasattr(opener, 'options') and 'defversion' in opener.options: v = opener.options['defversion'] if v & REVLOGNG: v |= REVLOGNGINLINEDATA if v & REVLOGNG and 'parentdelta' in opener.options: self._parentdelta = 1 if shallowroot: v |= REVLOGSHALLOW i = '' try: f = self.opener(self.indexfile) if "nonlazy" in getattr(self.opener, 'options', {}): i = f.read() else: i = f.read(_prereadsize) if len(i) > 0: v = struct.unpack(versionformat, i[:4])[0] except IOError, inst: if inst.errno != errno.ENOENT: raise self.version = v self._inline = v & REVLOGNGINLINEDATA self._shallow = v & REVLOGSHALLOW flags = v & ~0xFFFF fmt = v & 0xFFFF if fmt == REVLOGV0 and flags: raise RevlogError(_("index %s unknown flags %#04x for format v0") % (self.indexfile, flags >> 16)) elif fmt == REVLOGNG and flags & ~REVLOGNG_FLAGS: raise RevlogError(_("index %s unknown flags %#04x for revlogng") % (self.indexfile, flags >> 16)) elif fmt > REVLOGNG: raise RevlogError(_("index %s unknown format %d") % (self.indexfile, fmt)) self._io = revlogio() if self.version == REVLOGV0: self._io = revlogoldio() if i: try: d = self._io.parseindex(f, i, self._inline) except (ValueError, IndexError): raise RevlogError(_("index %s is corrupted") % (self.indexfile)) self.index, self.nodemap, self._chunkcache = d if not self._chunkcache: self._chunkclear() # add the magic null revision at -1 (if it hasn't been done already) if (self.index == [] or isinstance(self.index, lazyindex) or self.index[-1][7] != nullid) : self.index.append((0, 0, 0, -1, -1, -1, -1, nullid)) def _loadindex(self, start, end): """load a block of indexes all at once from the lazy parser""" if isinstance(self.index, lazyindex): self.index.p.loadindex(start, end) def _loadindexmap(self): """loads both the map and the index from the lazy parser""" if isinstance(self.index, lazyindex): p = self.index.p p.loadindex() self.nodemap = p.map def _loadmap(self): """loads the map from the lazy parser""" if isinstance(self.nodemap, lazymap): self.nodemap.p.loadmap() self.nodemap = self.nodemap.p.map def tip(self): return self.node(len(self.index) - 2) def __len__(self): return len(self.index) - 1 def __iter__(self): for i in xrange(len(self)): yield i def rev(self, node): try: return self.nodemap[node] except KeyError: raise LookupError(node, self.indexfile, _('no node')) def node(self, rev): return self.index[rev][7] def linkrev(self, rev): return self.index[rev][4] def parents(self, node): i = self.index d = i[self.rev(node)] return i[d[5]][7], i[d[6]][7] # map revisions to nodes inline def parentrevs(self, rev): return self.index[rev][5:7] def start(self, rev): return int(self.index[rev][0] >> 16) def end(self, rev): return self.start(rev) + self.length(rev) def length(self, rev): return self.index[rev][1] def base(self, rev): return self.index[rev][3] def flags(self, rev): return self.index[rev][0] & 0xFFFF def rawsize(self, rev): """return the length of the uncompressed text for a given revision""" l = self.index[rev][2] if l >= 0: return l t = self.revision(self.node(rev)) return len(t) size = rawsize def reachable(self, node, stop=None): """return the set of all nodes ancestral to a given node, including the node itself, stopping when stop is matched""" reachable = set((node,)) visit = [node] if stop: stopn = self.rev(stop) else: stopn = 0 while visit: n = visit.pop(0) if n == stop: continue if n == nullid: continue for p in self.parents(n): if self.rev(p) < stopn: continue if p not in reachable: reachable.add(p) visit.append(p) return reachable def ancestors(self, *revs): """Generate the ancestors of 'revs' in reverse topological order. Yield a sequence of revision numbers starting with the parents of each revision in revs, i.e., each revision is *not* considered an ancestor of itself. Results are in breadth-first order: parents of each rev in revs, then parents of those, etc. Result does not include the null revision.""" visit = list(revs) seen = set([nullrev]) while visit: for parent in self.parentrevs(visit.pop(0)): if parent not in seen: visit.append(parent) seen.add(parent) yield parent def descendants(self, *revs): """Generate the descendants of 'revs' in revision order. Yield a sequence of revision numbers starting with a child of some rev in revs, i.e., each revision is *not* considered a descendant of itself. Results are ordered by revision number (a topological sort).""" first = min(revs) if first == nullrev: for i in self: yield i return seen = set(revs) for i in xrange(first + 1, len(self)): for x in self.parentrevs(i): if x != nullrev and x in seen: seen.add(i) yield i break def findmissing(self, common=None, heads=None): """Return the ancestors of heads that are not ancestors of common. More specifically, return a list of nodes N such that every N satisfies the following constraints: 1. N is an ancestor of some node in 'heads' 2. N is not an ancestor of any node in 'common' The list is sorted by revision number, meaning it is topologically sorted. 'heads' and 'common' are both lists of node IDs. If heads is not supplied, uses all of the revlog's heads. If common is not supplied, uses nullid.""" if common is None: common = [nullid] if heads is None: heads = self.heads() common = [self.rev(n) for n in common] heads = [self.rev(n) for n in heads] # we want the ancestors, but inclusive has = set(self.ancestors(*common)) has.add(nullrev) has.update(common) # take all ancestors from heads that aren't in has missing = set() visit = [r for r in heads if r not in has] while visit: r = visit.pop(0) if r in missing: continue else: missing.add(r) for p in self.parentrevs(r): if p not in has: visit.append(p) missing = list(missing) missing.sort() return [self.node(r) for r in missing] def nodesbetween(self, roots=None, heads=None): """Return a topological path from 'roots' to 'heads'. Return a tuple (nodes, outroots, outheads) where 'nodes' is a topologically sorted list of all nodes N that satisfy both of these constraints: 1. N is a descendant of some node in 'roots' 2. N is an ancestor of some node in 'heads' Every node is considered to be both a descendant and an ancestor of itself, so every reachable node in 'roots' and 'heads' will be included in 'nodes'. 'outroots' is the list of reachable nodes in 'roots', i.e., the subset of 'roots' that is returned in 'nodes'. Likewise, 'outheads' is the subset of 'heads' that is also in 'nodes'. 'roots' and 'heads' are both lists of node IDs. If 'roots' is unspecified, uses nullid as the only root. If 'heads' is unspecified, uses list of all of the revlog's heads.""" nonodes = ([], [], []) if roots is not None: roots = list(roots) if not roots: return nonodes lowestrev = min([self.rev(n) for n in roots]) else: roots = [nullid] # Everybody's a descendent of nullid lowestrev = nullrev if (lowestrev == nullrev) and (heads is None): # We want _all_ the nodes! return ([self.node(r) for r in self], [nullid], list(self.heads())) if heads is None: # All nodes are ancestors, so the latest ancestor is the last # node. highestrev = len(self) - 1 # Set ancestors to None to signal that every node is an ancestor. ancestors = None # Set heads to an empty dictionary for later discovery of heads heads = {} else: heads = list(heads) if not heads: return nonodes ancestors = set() # Turn heads into a dictionary so we can remove 'fake' heads. # Also, later we will be using it to filter out the heads we can't # find from roots. heads = dict.fromkeys(heads, 0) # Start at the top and keep marking parents until we're done. nodestotag = set(heads) # Remember where the top was so we can use it as a limit later. highestrev = max([self.rev(n) for n in nodestotag]) while nodestotag: # grab a node to tag n = nodestotag.pop() # Never tag nullid if n == nullid: continue # A node's revision number represents its place in a # topologically sorted list of nodes. r = self.rev(n) if r >= lowestrev: if n not in ancestors: # If we are possibly a descendent of one of the roots # and we haven't already been marked as an ancestor ancestors.add(n) # Mark as ancestor # Add non-nullid parents to list of nodes to tag. nodestotag.update([p for p in self.parents(n) if p != nullid]) elif n in heads: # We've seen it before, is it a fake head? # So it is, real heads should not be the ancestors of # any other heads. heads.pop(n) if not ancestors: return nonodes # Now that we have our set of ancestors, we want to remove any # roots that are not ancestors. # If one of the roots was nullid, everything is included anyway. if lowestrev > nullrev: # But, since we weren't, let's recompute the lowest rev to not # include roots that aren't ancestors. # Filter out roots that aren't ancestors of heads roots = [n for n in roots if n in ancestors] # Recompute the lowest revision if roots: lowestrev = min([self.rev(n) for n in roots]) else: # No more roots? Return empty list return nonodes else: # We are descending from nullid, and don't need to care about # any other roots. lowestrev = nullrev roots = [nullid] # Transform our roots list into a set. descendents = set(roots) # Also, keep the original roots so we can filter out roots that aren't # 'real' roots (i.e. are descended from other roots). roots = descendents.copy() # Our topologically sorted list of output nodes. orderedout = [] # Don't start at nullid since we don't want nullid in our output list, # and if nullid shows up in descedents, empty parents will look like # they're descendents. for r in xrange(max(lowestrev, 0), highestrev + 1): n = self.node(r) isdescendent = False if lowestrev == nullrev: # Everybody is a descendent of nullid isdescendent = True elif n in descendents: # n is already a descendent isdescendent = True # This check only needs to be done here because all the roots # will start being marked is descendents before the loop. if n in roots: # If n was a root, check if it's a 'real' root. p = tuple(self.parents(n)) # If any of its parents are descendents, it's not a root. if (p[0] in descendents) or (p[1] in descendents): roots.remove(n) else: p = tuple(self.parents(n)) # A node is a descendent if either of its parents are # descendents. (We seeded the dependents list with the roots # up there, remember?) if (p[0] in descendents) or (p[1] in descendents): descendents.add(n) isdescendent = True if isdescendent and ((ancestors is None) or (n in ancestors)): # Only include nodes that are both descendents and ancestors. orderedout.append(n) if (ancestors is not None) and (n in heads): # We're trying to figure out which heads are reachable # from roots. # Mark this head as having been reached heads[n] = 1 elif ancestors is None: # Otherwise, we're trying to discover the heads. # Assume this is a head because if it isn't, the next step # will eventually remove it. heads[n] = 1 # But, obviously its parents aren't. for p in self.parents(n): heads.pop(p, None) heads = [n for n in heads.iterkeys() if heads[n] != 0] roots = list(roots) assert orderedout assert roots assert heads return (orderedout, roots, heads) def heads(self, start=None, stop=None): """return the list of all nodes that have no children if start is specified, only heads that are descendants of start will be returned if stop is specified, it will consider all the revs from stop as if they had no children """ if start is None and stop is None: count = len(self) if not count: return [nullid] ishead = [1] * (count + 1) index = self.index for r in xrange(count): e = index[r] ishead[e[5]] = ishead[e[6]] = 0 return [self.node(r) for r in xrange(count) if ishead[r]] if start is None: start = nullid if stop is None: stop = [] stoprevs = set([self.rev(n) for n in stop]) startrev = self.rev(start) reachable = set((startrev,)) heads = set((startrev,)) parentrevs = self.parentrevs for r in xrange(startrev + 1, len(self)): for p in parentrevs(r): if p in reachable: if r not in stoprevs: reachable.add(r) heads.add(r) if p in heads and p not in stoprevs: heads.remove(p) return [self.node(r) for r in heads] def children(self, node): """find the children of a given node""" c = [] p = self.rev(node) for r in range(p + 1, len(self)): prevs = [pr for pr in self.parentrevs(r) if pr != nullrev] if prevs: for pr in prevs: if pr == p: c.append(self.node(r)) elif p == nullrev: c.append(self.node(r)) return c def descendant(self, start, end): if start == nullrev: return True for i in self.descendants(start): if i == end: return True elif i > end: break return False def ancestor(self, a, b): """calculate the least common ancestor of nodes a and b""" # fast path, check if it is a descendant a, b = self.rev(a), self.rev(b) start, end = sorted((a, b)) if self.descendant(start, end): return self.node(start) def parents(rev): return [p for p in self.parentrevs(rev) if p != nullrev] c = ancestor.ancestor(a, b, parents) if c is None: return nullid return self.node(c) def _match(self, id): if isinstance(id, (long, int)): # rev return self.node(id) if len(id) == 20: # possibly a binary node # odds of a binary node being all hex in ASCII are 1 in 10**25 try: node = id self.rev(node) # quick search the index return node except LookupError: pass # may be partial hex id try: # str(rev) rev = int(id) if str(rev) != id: raise ValueError if rev < 0: rev = len(self) + rev if rev < 0 or rev >= len(self): raise ValueError return self.node(rev) except (ValueError, OverflowError): pass if len(id) == 40: try: # a full hex nodeid? node = bin(id) self.rev(node) return node except (TypeError, LookupError): pass def _partialmatch(self, id): if len(id) < 40: try: # hex(node)[:...] l = len(id) // 2 # grab an even number of digits bin_id = bin(id[:l * 2]) nl = [n for n in self.nodemap if n[:l] == bin_id] nl = [n for n in nl if hex(n).startswith(id)] if len(nl) > 0: if len(nl) == 1: return nl[0] raise LookupError(id, self.indexfile, _('ambiguous identifier')) return None except TypeError: pass def lookup(self, id): """locate a node based on: - revision number or str(revision number) - nodeid or subset of hex nodeid """ n = self._match(id) if n is not None: return n n = self._partialmatch(id) if n: return n raise LookupError(id, self.indexfile, _('no match found')) def cmp(self, node, text): """compare text with a given file revision returns True if text is different than what is stored. """ p1, p2 = self.parents(node) return hash(text, p1, p2) != node def _addchunk(self, offset, data): o, d = self._chunkcache # try to add to existing cache if o + len(d) == offset and len(d) + len(data) < _prereadsize: self._chunkcache = o, d + data else: self._chunkcache = offset, data def _loadchunk(self, offset, length): if self._inline: df = self.opener(self.indexfile) else: df = self.opener(self.datafile) readahead = max(65536, length) df.seek(offset) d = df.read(readahead) self._addchunk(offset, d) if readahead > length: return d[:length] return d def _getchunk(self, offset, length): o, d = self._chunkcache l = len(d) # is it in the cache? cachestart = offset - o cacheend = cachestart + length if cachestart >= 0 and cacheend <= l: if cachestart == 0 and cacheend == l: return d # avoid a copy return d[cachestart:cacheend] return self._loadchunk(offset, length) def _chunkraw(self, startrev, endrev): start = self.start(startrev) length = self.end(endrev) - start if self._inline: start += (startrev + 1) * self._io.size return self._getchunk(start, length) def _chunk(self, rev): return decompress(self._chunkraw(rev, rev)) def _chunkclear(self): self._chunkcache = (0, '') def deltaparent(self, rev): """return previous revision or parentrev according to flags""" if self.flags(rev) & REVIDX_PARENTDELTA: return self.parentrevs(rev)[0] else: return rev - 1 def revdiff(self, rev1, rev2): """return or calculate a delta between two revisions""" if self.base(rev2) != rev2 and self.deltaparent(rev2) == rev1: return self._chunk(rev2) return mdiff.textdiff(self.revision(self.node(rev1)), self.revision(self.node(rev2))) def revision(self, node): """return an uncompressed revision of a given node""" cachedrev = None if node == nullid: return "" if self._cache: if self._cache[0] == node: return self._cache[2] cachedrev = self._cache[1] # look up what we need to read text = None rev = self.rev(node) base = self.base(rev) # check rev flags if self.flags(rev) & ~REVIDX_KNOWN_FLAGS: raise RevlogError(_('incompatible revision flag %x') % (self.flags(rev) & ~REVIDX_KNOWN_FLAGS)) # build delta chain self._loadindex(base, rev + 1) chain = [] index = self.index # for performance iterrev = rev e = index[iterrev] while iterrev != base and iterrev != cachedrev: chain.append(iterrev) if e[0] & REVIDX_PARENTDELTA: iterrev = e[5] else: iterrev -= 1 e = index[iterrev] chain.reverse() base = iterrev if iterrev == cachedrev: # cache hit text = self._cache[2] # drop cache to save memory self._cache = None self._chunkraw(base, rev) if text is None: text = self._chunk(base) bins = [self._chunk(r) for r in chain] text = mdiff.patches(text, bins) p1, p2 = self.parents(node) if (node != hash(text, p1, p2) and not (self.flags(rev) & REVIDX_PUNCHED_FLAG)): raise RevlogError(_("integrity check failed on %s:%d") % (self.indexfile, rev)) self._cache = (node, rev, text) return text def checkinlinesize(self, tr, fp=None): if not self._inline or (self.start(-2) + self.length(-2)) < _maxinline: return trinfo = tr.find(self.indexfile) if trinfo is None: raise RevlogError(_("%s not found in the transaction") % self.indexfile) trindex = trinfo[2] dataoff = self.start(trindex) tr.add(self.datafile, dataoff) if fp: fp.flush() fp.close() df = self.opener(self.datafile, 'w') try: for r in self: df.write(self._chunkraw(r, r)) finally: df.close() fp = self.opener(self.indexfile, 'w', atomictemp=True) self.version &= ~(REVLOGNGINLINEDATA) self._inline = False for i in self: e = self._io.packentry(self.index[i], self.node, self.version, i) fp.write(e) # if we don't call rename, the temp file will never replace the # real index fp.rename() tr.replace(self.indexfile, trindex * self._io.size) self._chunkclear() def addrevision(self, text, transaction, link, p1, p2, cachedelta=None): """add a revision to the log text - the revision data to add transaction - the transaction object used for rollback link - the linkrev data to add p1, p2 - the parent nodeids of the revision cachedelta - an optional precomputed delta """ node = hash(text, p1, p2) if (node in self.nodemap and (not self.flags(self.rev(node)) & REVIDX_PUNCHED_FLAG)): return node dfh = None if not self._inline: dfh = self.opener(self.datafile, "a") ifh = self.opener(self.indexfile, "a+") try: return self._addrevision(node, text, transaction, link, p1, p2, cachedelta, ifh, dfh) finally: if dfh: dfh.close() ifh.close() def _addrevision(self, node, text, transaction, link, p1, p2, cachedelta, ifh, dfh): btext = [text] def buildtext(): if btext[0] is not None: return btext[0] # flush any pending writes here so we can read it in revision if dfh: dfh.flush() ifh.flush() basetext = self.revision(self.node(cachedelta[0])) btext[0] = mdiff.patch(basetext, cachedelta[1]) chk = hash(btext[0], p1, p2) if chk != node: raise RevlogError(_("consistency error in delta")) return btext[0] def builddelta(rev): # can we use the cached delta? if cachedelta and cachedelta[0] == rev: delta = cachedelta[1] else: t = buildtext() ptext = self.revision(self.node(rev)) delta = mdiff.textdiff(ptext, t) data = compress(delta) l = len(data[1]) + len(data[0]) base = self.base(rev) dist = l + offset - self.start(base) return dist, l, data, base curr = len(self) prev = curr - 1 base = curr offset = self.end(prev) flags = 0 d = None p1r, p2r = self.rev(p1), self.rev(p2) # should we try to build a delta? if prev != nullrev: d = builddelta(prev) if self._parentdelta and prev != p1r: d2 = builddelta(p1r) if d2 < d: d = d2 flags = REVIDX_PARENTDELTA dist, l, data, base = d # full versions are inserted when the needed deltas # become comparable to the uncompressed text # or the base revision is punched if text is None: textlen = mdiff.patchedsize(self.rawsize(cachedelta[0]), cachedelta[1]) else: textlen = len(text) if (d is None or dist > textlen * 2 or (self.flags(base) & REVIDX_PUNCHED_FLAG)): text = buildtext() data = compress(text) l = len(data[1]) + len(data[0]) base = curr e = (offset_type(offset, flags), l, textlen, base, link, p1r, p2r, node) self.index.insert(-1, e) self.nodemap[node] = curr entry = self._io.packentry(e, self.node, self.version, curr) if not self._inline: transaction.add(self.datafile, offset) transaction.add(self.indexfile, curr * len(entry)) if data[0]: dfh.write(data[0]) dfh.write(data[1]) dfh.flush() ifh.write(entry) else: offset += curr * self._io.size transaction.add(self.indexfile, offset, curr) ifh.write(entry) ifh.write(data[0]) ifh.write(data[1]) self.checkinlinesize(transaction, ifh) if type(text) == str: # only accept immutable objects self._cache = (node, curr, text) return node def group(self, nodelist, lookup, infocollect=None, fullrev=False): """Calculate a delta group, yielding a sequence of changegroup chunks (strings). Given a list of changeset revs, return a set of deltas and metadata corresponding to nodes. The first delta is first parent(nodelist[0]) -> nodelist[0], the receiver is guaranteed to have this parent as it has all history before these changesets. In the case firstparent is nullrev the changegroup starts with a full revision. fullrev forces the insertion of the full revision, necessary in the case of shallow clones where the first parent might not exist at the reciever. """ revs = [self.rev(n) for n in nodelist] # if we don't have any revisions touched by these changesets, bail if not revs: yield changegroup.closechunk() return # add the parent of the first rev p = self.parentrevs(revs[0])[0] revs.insert(0, p) if p == nullrev: fullrev = True # build deltas for d in xrange(len(revs) - 1): a, b = revs[d], revs[d + 1] nb = self.node(b) if infocollect is not None: infocollect(nb) p = self.parents(nb) meta = nb + p[0] + p[1] + lookup(nb) if fullrev: d = self.revision(nb) meta += mdiff.trivialdiffheader(len(d)) fullrev = False else: d = self.revdiff(a, b) yield changegroup.chunkheader(len(meta) + len(d)) yield meta yield d yield changegroup.closechunk() def addgroup(self, bundle, linkmapper, transaction): """ add a delta group given a set of deltas, add them to the revision log. the first delta is against its parent, which should be in our log, the rest are against the previous delta. """ # track the base of the current delta log node = None r = len(self) end = 0 if r: end = self.end(r - 1) ifh = self.opener(self.indexfile, "a+") isize = r * self._io.size if self._inline: transaction.add(self.indexfile, end + isize, r) dfh = None else: transaction.add(self.indexfile, isize, r) transaction.add(self.datafile, end) dfh = self.opener(self.datafile, "a") try: # loop through our set of deltas chain = None while 1: chunkdata = bundle.parsechunk() if not chunkdata: break node = chunkdata['node'] p1 = chunkdata['p1'] p2 = chunkdata['p2'] cs = chunkdata['cs'] delta = chunkdata['data'] link = linkmapper(cs) if (node in self.nodemap and (not self.flags(self.rev(node)) & REVIDX_PUNCHED_FLAG)): # this can happen if two branches make the same change chain = node continue for p in (p1, p2): if not p in self.nodemap: if self._shallow: # add null entries for missing parents # XXX FIXME #if base == nullrev: # base = len(self) #e = (offset_type(end, REVIDX_PUNCHED_FLAG), # 0, 0, base, nullrev, nullrev, nullrev, p) #self.index.insert(-1, e) #self.nodemap[p] = r #entry = self._io.packentry(e, self.node, # self.version, r) #ifh.write(entry) #t, r = r, r + 1 raise LookupError(p, self.indexfile, _('unknown parent')) else: raise LookupError(p, self.indexfile, _('unknown parent')) if not chain: # retrieve the parent revision of the delta chain chain = p1 if not chain in self.nodemap: raise LookupError(chain, self.indexfile, _('unknown base')) chainrev = self.rev(chain) chain = self._addrevision(node, None, transaction, link, p1, p2, (chainrev, delta), ifh, dfh) if not dfh and not self._inline: # addrevision switched from inline to conventional # reopen the index dfh = self.opener(self.datafile, "a") ifh = self.opener(self.indexfile, "a") finally: if dfh: dfh.close() ifh.close() return node def strip(self, minlink, transaction): """truncate the revlog on the first revision with a linkrev >= minlink This function is called when we're stripping revision minlink and its descendants from the repository. We have to remove all revisions with linkrev >= minlink, because the equivalent changelog revisions will be renumbered after the strip. So we truncate the revlog on the first of these revisions, and trust that the caller has saved the revisions that shouldn't be removed and that it'll readd them after this truncation. """ if len(self) == 0: return if isinstance(self.index, lazyindex): self._loadindexmap() for rev in self: if self.index[rev][4] >= minlink: break else: return # first truncate the files on disk end = self.start(rev) if not self._inline: transaction.add(self.datafile, end) end = rev * self._io.size else: end += rev * self._io.size transaction.add(self.indexfile, end) # then reset internal state in memory to forget those revisions self._cache = None self._chunkclear() for x in xrange(rev, len(self)): del self.nodemap[self.node(x)] del self.index[rev:-1] def checksize(self): expected = 0 if len(self): expected = max(0, self.end(len(self) - 1)) try: f = self.opener(self.datafile) f.seek(0, 2) actual = f.tell() dd = actual - expected except IOError, inst: if inst.errno != errno.ENOENT: raise dd = 0 try: f = self.opener(self.indexfile) f.seek(0, 2) actual = f.tell() s = self._io.size i = max(0, actual // s) di = actual - (i * s) if self._inline: databytes = 0 for r in self: databytes += max(0, self.length(r)) dd = 0 di = actual - len(self) * s - databytes except IOError, inst: if inst.errno != errno.ENOENT: raise di = 0 return (dd, di) def files(self): res = [self.indexfile] if not self._inline: res.append(self.datafile) return res